Electric dental heater.



W. & D. ASGH.

ELECTRIC DENTAL HEATER.

APPLICATION FILED DBO. 22, 1910.

Patented Nov. 14, 1911.

UNITED STATES PATENT OFFICE.

WLADISLAW ASCH AIS D DAGOBEB'I. ASCII, BERLIN, GERMANY.

ELECTRIC nnn'r'ar. HEATER.

Specification of Letters Patent. i

Patented Nov. 14, 1911.

Application filed December 22, 1910. Serial No. 598,790.

To all whom it ma concern:

Be it known t at we, VVLADISLAW ASCII and DAGOBERT AsoH, subjects of theGerman Emperor, residing at Berlin, Germany, have invented new anduseful Improvements in Electric Dental Heaters, of which the followingis a specification.

In many industrial branches cementlike materials are employed in largequantities, so for maritime and ordinary building purposes and also inmanufacturing artistic products. For a number of years cements have beenused in dentistry for filling up cavities in teeth; The cements used forthe latter purpose are distinguished as dental cements which arenon-transparent, and dental cements which have a transparent gloss andthereby resemble the natural enamel of the teeth.

The length of time required by cements to harden is different. The finergrained the cement powder, the quicker it will set; the contents ofliquid matter in the cement compound plays a further important part inthis respect. So for instance with dental cements, with which solutionsof acids andsalts are employed, the latter must be more or less dilutedor concentrated accordingly as rapid or slowly setting cements are to beused. In most cases a cement compound will be desirable, with which thesetting process commences slowly, so that the mixed cement may be giventhe desired shape or form. When then the block of cement has beenprepared, it should pass as quickly as possible through the varioussetting phases. In dentistry the conditions will be as follows While heis preparing the filling the dentist will want the cement to set slowly;but when he has introduced the filling into the cavity in the tooth, andhas given it the necessary shape, he wants the cement to set as quicklyas possible, so that he may be able to grind it off soon and the settingwill not be extended too long.

The object of the present invention is the solution of this problem.

The compound may be of a slowly setting character, so that it will allowof being conveniently formed into blocks, artistic articles, dentalfillings, whereupon the setting process is artificially accelerated, sothat the settin phases may be even more rapid than wit quickly settingcements.

It is a known fact, that chemical reactions always proceed considerablyquicker at higher temperatures, and also the chemical setting process isactually accelerated by heat. A cement, for instance, which will set at.a temperature of 18 (1., in about 15 minutes, will go through thesetting phases in two to three minutes at a temperature of 37 C.Heretofore heat has never yet been I employed in building for thepurpose of accelerating the setting, and in dentistry only in anunsatisfactory manner by means of a hot air-blower. This has thefollowing disadvantages. is immediately applied to the filling. By theefiect of the hot iron tube the cement is too quickly heated to a hightemperature, so that it will crack or become very brittle.

The durability of the filling is thereby imaired. 2. By 'means of thehot air-blower it is not possible to heat the cement continuously forany length of timeas the glowing hot iron-tube of the blower will sooncool. If the filling is to be kept hot for any length of time by meansof the hot air-blower, the latter will have to be repeatedly heated. 3.A rapid supply of heat, of high temperatures will almost always causethe patient pain and is almost impossible with sensitive patients. 4. Alarge number of the silicate cements on the market are even brittle whenallowed to set under ordinary conditions and their brittleness isconsiderably increased by the rapid supply of heat of high degrees.

The essential feature of the present invention consists in a continuoussupply of heat in such a manner, that the temperature of the source ofheat rises gradually, the

1. Heat of a high degree supply of heat being regulable, so thatonlyments on the market is obtained.

In the accompanying drawing an appa ratus is exemplified, which may beused in carrying out the present method in dentistry.

Figure 1 is the apparatus in side elevation and partly in section,connected to an electric source of current. V Fig. 2 is the upper end ofthe left leg of the tongs in longitudinal section; Fig. 3 is the upperend of the right leg in elevation. Fig. 4 is'a section along the line4-4 in Fig. 1.

The apparatus consists of a kind of tongs the legs 1 and 2 are solderedor otherwise connected wit-h each other at 3. The legs 1 and 2 arehollow and bent over at their free ends at right angles into parallelplanes. The parts 4 thus bent over areclosed at their 'free ends withsleeve-like members, which are secured to the ends of the legs 1 and 2by a screw-joint. The sleeves 4 form the jaws of the tongs and serve toreceive an electric glow-lamp 5. The inner sides of the jaws 4 areprovided with perforations 6 to permit the rays of light to passtherethrough. The glow-lamp 5 contains a filament extendinglongitudinally through the same, which terminates at both ends incontacts 7 and 8, of which the one 7 is in electric connection with thesleeve 4, whereas the other is in contact with a contact piece 10insulatedly fitted into the free end of the tubular leg. From thiscontact piece an electric conductor 11 leads through the hollow leg to aterminal 12, which is insulatedly fitted on a clasp 13 secured to thelegs 1 and 2 close to their joint.

From this terminal a second wire 14 leads through the other hollow legto a second glow-lamp, which is arranged and fitted in a similar mannerin the second jaw 4. The clasp 13 has a second terminal 15, which isconductively connected with the clasp. On the legs 1 and 2 a sleeve 16is displaceably fitted, which serves to approach the jaws 4 to eachother according to requirement. The jaws are automatically separatedfrom each other, on the sleeve 16 being pushed back, in consequence ofthe elasticity of-the" legs.

To the terminals 12 and 15'respectively are connected conductors 17 and18. which resistance 22 in a common box receptacle 23.

The series resistance 22, which is ofa known type, is connected to thecircuit leading to the lamps 5 of the tongs. By displacing the contactpiece 24 of the series resistance the current may be varied at will andthereby the heat to be transmitted by the lamps may be gaged. In someinstances the series resistances may be omitted, if desired, without inany way departing from the spirit of the invention. In place of theclasp 13 also the slide 16 may be adapted to carry the terminals. Theslide may also serve to interrupt the contact of the lamp circuit. Whenthe contact is closed, the lamps will be supplied with electric energy,which will be converted into heat and light energy, as the smallelectric lamps will radiate much heat in the .red rays.

v The device is particularly applicable for transparent cements, as therays of light will penetrate the transparent material and provideschemical reactions which assist in the v hardening process. This resultsin a rapid acceleration of the setting process, without the cement beingin any way deteriorated.

For diiferent cements of course different modifications of the apparatuswill have to be employed. The principle of the supply of heat will,however, always remain the same: the conversion of electric energy intoheat and light energy, the regulation of this heat and light energy byinterpolation of resistances.

It is obvious that other source of heat, may be employed foraccelerating the setting, provided the conditions are met with, that theheat is gradually increased, regulable and of continuous effect.

We claim:

1. An apparatus for hardening cement fillings in teeth, consisting ofhollow tongs having teeth-engaging portions, said teethengagmg portionsbeing provided with aper tures in their teeth-engaging surfacescommunicatlng with the interior of the tongs,

electric heating elements positioned within said tongs and adjacent.said apertures whereby the electrical energy will be direct ed throughsaid apertures upon the tooth which is being filled, and means forsupply-- ing an electric current to said elements.

2. An apparatus for hardening cement fillings in teeth, consisting ofhollow ,tongs having teeth-engaging portions, said teethengagmg portionsbeing provided with apertures in their teeth-engaging portionscommunicating with the interior of the tongs, electric lamps positionedwithin said tongs adjacent said apertures, whereby the light from thelamps will pass through said apertures and will be directed upon thetooth which is being filled, and means for supplying an electric currentto said lamps.

3. An apparatus for hardening cement fillings in teeth consisting oftongs with hollow legs, the ends of said legs bent over at anglesandadapted to form hollow jaws, electric "glow-lamps in said jaws,apertures in the inner sides of said jaws, conductors foran electriccurrent in said hollow aws and a source of currentconnected to saidconductors.

terminals and a regulableresistance in-series with said connectingconductors.

5. An apparatus for hardening cement fillings in teeth consisting oftongs,- with hollow legs, the ends of said legs bent said hollow jaws,contact pieces on both ends of said glow-lamps, some of said contactlatedly fitted in said hollow legs, a clasp'-' over at right angles andadapted to form.

hollow jaws, said jaws unscrewable and having a plurality of aperturesin the inner side's, electric glow-lamps loosely fitted in piecesbearing against the wallsfof said jaws, others bearing against contactpieces insusaid contact pieces, at their other ends with the saidinsulated terminal, a slide displaceably fitted on the legs of the tongsadapted to approach these to each other when dis placed and means ofsupplying an electric current to said terminals.

In testimony whereof we have signed our names to this specification inthe presence of two subscribing witnesses.

WLADISLAW ASCH; DAGOBERT ASCH.

Witnesses WQLDEMAR HAUPT, HENRY HASPER.

